Because of continual technological advancements in semiconductor manufacturing, geometries of semiconductor devices are shrinking. Thus, transistor density continues to grow. As process geometries shrink and leakage currents increase, a dramatic increase in device current at burn-in conditions (temperature and voltage) is seen. Burn-in conditions may cause extremely high IDDQ currents, which may create thermal and power issues and could potentially cause thermal runaway on strong material. Thermal runaway is a phenomenon where a device draws more current as it gets hotter, which results in more self-heating and may eventually lead to junction temperatures high enough to melt the package and possibly the test hardware.
New model burn-in ovens facilitate meeting an increased demand for current, but do little to combat the resulting thermal consequences. For example, the Aehr Max 4 ovens only provide temperature control on the oven level. Some expensive oven options allow for individual device temperature monitoring and regulation of fan control to prevent thermal runaway, except these ovens are expensive and do not facilitate optimal burn-in conditions. Consequently, common temperature set points must be found that will accommodate a wide range of potential device current needs.